U.S. authorities are going after corrupt traders with renewed vigour.

The number of new FBI investigations into insider trading shot up 43% nationwide for the fiscal year that ended September 30, according to a report on FT.

Read: Hedge fund founder convicted of insider trading

“Since 2009, criminal charges have been filed against 72 hedge fund traders, company insiders and consultants by Manhattan prosecutors alone,” said the report.

In one of the biggest insider trading cases, the prosecutors last year won the conviction of Raj Rajaratnam, the founder of Galleon Group, and others in a ring of insider trading. In another high-profile conviction earlier this year, Rajat Gupta, the former director of Goldman Sachs, was charged as part of the crackdown.

Read: Former RIM employee conducted insider trading: OSC

As part of the initiative, FBI agents are working with market regulators to detect trading irregularities and sharp swings in biotech and pharma stocks. U.S. authorities are working collaboratively with Wall Street insiders and U.K. regulators to bring unscrupulous traders to book.

Read: Gupta is guilty